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/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/Types.h>
#include <LibC/sys/arch/i386/regs.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <syscall.h>
#include <unistd.h>
static int g_pid = -1;
static void handle_sigint(int)
{
if (g_pid == -1)
return;
if (ptrace(PT_DETACH, g_pid, 0, 0) == -1) {
perror("detach");
}
}
int main(int argc, char** argv)
{
if (pledge("stdio wpath cpath proc exec ptrace sigaction", nullptr) < 0) {
perror("pledge");
return 1;
}
Vector<const char*> child_argv;
const char* output_filename = nullptr;
auto trace_file = Core::File::standard_error();
Core::ArgsParser parser;
parser.set_stop_on_first_non_option(true);
parser.set_general_help(
"Trace all syscalls and their result.");
parser.add_option(g_pid, "Trace the given PID", "pid", 'p', "pid");
parser.add_option(output_filename, "Filename to write output to", "output", 'o', "output");
parser.add_positional_argument(child_argv, "Arguments to exec", "argument", Core::ArgsParser::Required::No);
parser.parse(argc, argv);
if (output_filename != nullptr) {
auto open_result = Core::File::open(output_filename, Core::OpenMode::WriteOnly);
if (open_result.is_error()) {
outln(stderr, "Failed to open output file: {}", open_result.error());
return 1;
}
trace_file = open_result.value();
}
if (pledge("stdio proc exec ptrace sigaction", nullptr) < 0) {
perror("pledge");
return 1;
}
int status;
if (g_pid == -1) {
if (child_argv.is_empty()) {
warnln("strace: Expected either a pid or some arguments");
return 1;
}
child_argv.append(nullptr);
int pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (!pid) {
if (ptrace(PT_TRACE_ME, 0, 0, 0) == -1) {
perror("traceme");
return 1;
}
int rc = execvp(child_argv.first(), const_cast<char**>(child_argv.data()));
if (rc < 0) {
perror("execvp");
exit(1);
}
VERIFY_NOT_REACHED();
}
g_pid = pid;
if (waitpid(pid, &status, WSTOPPED | WEXITED) != pid || !WIFSTOPPED(status)) {
perror("waitpid");
return 1;
}
}
struct sigaction sa;
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_handler = handle_sigint;
sigaction(SIGINT, &sa, nullptr);
if (ptrace(PT_ATTACH, g_pid, 0, 0) == -1) {
perror("attach");
return 1;
}
if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
perror("waitpid");
return 1;
}
for (;;) {
if (ptrace(PT_SYSCALL, g_pid, 0, 0) == -1) {
perror("syscall");
return 1;
}
if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
perror("wait_pid");
return 1;
}
PtraceRegisters regs = {};
if (ptrace(PT_GETREGS, g_pid, ®s, 0) == -1) {
perror("getregs");
return 1;
}
#if ARCH(I386)
u32 syscall_index = regs.eax;
u32 arg1 = regs.edx;
u32 arg2 = regs.ecx;
u32 arg3 = regs.ebx;
#else
u64 syscall_index = regs.rax;
u64 arg1 = regs.rdx;
u64 arg2 = regs.rcx;
u64 arg3 = regs.rbx;
#endif
if (ptrace(PT_SYSCALL, g_pid, 0, 0) == -1) {
perror("syscall");
return 1;
}
if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
perror("wait_pid");
return 1;
}
if (ptrace(PT_GETREGS, g_pid, ®s, 0) == -1) {
perror("getregs");
return 1;
}
#if ARCH(I386)
u32 res = regs.eax;
#else
u64 res = regs.rax;
#endif
auto string = String::formatted("{}({:#08x}, {:#08x}, {:#08x})\t={}\n",
Syscall::to_string((Syscall::Function)syscall_index),
arg1,
arg2,
arg3,
res);
if (!trace_file->write(string)) {
warnln("write: {}", trace_file->error_string());
return 1;
}
}
return 0;
}
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